Check if variable is undefined not working [duplicate]

Question

I want to check if a variable is undefined and quickly found some stackoverflow answers that said the correct way to do it is to test if(variable==null). But in Chrome I am getting an error saying: Uncaught ReferenceError: xdate is not defined

Huh? The whole reason I am testing is so I don't get errors like this. And I did it just like the approved stackoverflow answers. Here is my code snippet.

        if (xdate == null){
          var dateadd = "";
        } else {
          var dateadd = "&date="+date;
        }

can you verify if the error is on a different line in your console? — gurvinder372
– gurvinder372, Commented Mar 16, 2016 at 14:08
Unfortunately, there's a difference between "undefined" and "undeclared" - it looks like in your code it doesn't exist, ie is undeclared. jsfiddle.net/2om07p3d — fdomn-m
– fdomn-m, Commented Mar 16, 2016 at 14:18

Pandiyan Cool · Accepted Answer · 2016-03-16 14:08:43Z

4

use something like this to verify whether variable is undefined or not

if (typeof something === "undefined") {
    alert("something is undefined");
}

edited Mar 16, 2016 at 14:08

answered Mar 16, 2016 at 14:07

Pandiyan Cool

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1 Comment

Thread7 Over a year ago

using typeof doesn't cause the error for me. So I am going with this.

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